Topologically modified tools were used, for example, in DE 102012015846A1, EP 1995010A1, WO 2010/060596A1, DE 19624842A1, DE 19706867, DE 102005030846A1 and DE 102006061759A1 to produce a corresponding topological modification on the workpiece by way of a diagonal generating method. The diagonal ratio was selected for this purpose such that the contact path with the workpiece sweeps over a defined region of the tool in which the topological modification is applied during a machining stroke so that the topological modification is applied to the workpiece.
Profile modifications were in contrast typically implemented in accordance with the prior art in that the tool is dressed using a dresser which provides the desired modification of the profile shape and transfers it to the tool during dressing. In generating machining, the modification is then transferred to the workpiece.
However, this has the disadvantage that a corresponding dresser has to be produced for each desired profile modification. The cost and time effort associated herewith is not worthwhile in every situation in this respect.
Alternatively, the desired profile shape on the tool can also be produced by contour dressing. The contour dressing is, however, very time-intensive and additionally produces an unwanted surface roughness in many cases.
It is there for the object of the present disclosure to provide an improved method for producing a workpiece having a modified gearing geometry.
The present disclosure comprises a method of producing a workpiece having a modified gearing geometry by a generating method, wherein the workpiece is generating machined in at least one machining stroke by a tool having a modified gearing geometry, with the tool having a topological modification. The method in accordance with the present disclosure is characterized in that the contact path with the workpiece is not shifted on the tool during the machining stroke.
The inventor of the present disclosure has recognized that topologically modified tools can also be used to produce a profile modification of the workpiece machined by the generating method. A method is hereby provided which can be realized inexpensively and fast and by which profile modifications can also be produced on a workpiece without a correspondingly modified dresser and without the use of a contour dressing process. This is achieved in that, unlike with the use of topologically modified tools known from the prior art, the contact path is no longer shifted over a defined region of the tool, but rather remains unchanged over the machining stroke. The total width of the workpiece is thus machined with the same contact path of the tool. As a result, no topological modification results on the workpiece, despite the topologically modified tool; rather, a profile modification results.
The present disclosure is optionally used for producing gear wheels with a gearing of a spur gear. The workpieces can furthermore have both a cylindrical and a conical basic shape.
In a first embodiment of the present disclosure, the method in accordance with the present disclosure is used for machining a cylindrical workpiece. In this case, the machining of the workpiece optionally takes place by an axial generating method, e.g. without a shifting of the tool along its axis of rotation during the machining stroke. It is ensured by the axial generating method that the contact path on the tool is not shifted during the machining stroke.
In a second embodiment of the present disclosure, the method in accordance with the present disclosure is used for machining a conical workpiece. In this case, the machining of the workpiece optionally takes place by a diagonal generating method, wherein the diagonal ratio is selected such that the contact path on the tool does not shift during the machining stroke. Unlike in the machining of a cylindrical workpiece, an axial generating method in the machining of a conical workpiece would result in a shift of the contact path on the tool. The machining of conical workpieces in accordance with the method in accordance with the present disclosure therefore requires the use of a diagonal generating method to ensure by a corresponding shifting of the tool along its axis of rotation during the machining stroke that the contact path does not shift.
In a first variant, a tool having a cylindrical basic shape is used. In this case, the machining optionally takes place at one flank. This is due to the fact that different diagonal ratios are generally necessary for the left and right flanks so that the contact path is not shifted. A two-flank machining of the workpiece is therefore generally no longer possible.
In a second variant, a tool having a conical basic shape is used in contrast. A further degree of freedom is available with the conical angle due to the use of a conical tool and said degree of freedom can be selected such that a two-flank machining in accordance with the method in accordance with the present disclosure becomes possible. On the use of a tool having a conical basic shape, the machining of the workpiece therefore optionally takes place on two flanks, with the conical angle of the tool and the diagonal ratio further optionally being selected such that the contact path does not shift on the right and left flanks in the two-flank machining.
Embodiments of the present disclosure which can be used both for machining cylindrical workpieces and for machining conical workpieces will be described in the following.
A topological modification of the tool means that the tool has a combination of a profile modification and a tooth trace modification.
In accordance with a first embodiment of the present disclosure, the topological modification of the surface geometry of the tool can have a constant value in the generating pattern at least locally in a first direction of the tool and can be given by a function FFt1 in a second direction of the tool which extends perpendicular to the first direction. The topological modification is optionally also globally given in this manner in at least one region of the tool. Such topological modifications can be applied relatively simply to the tool and nevertheless allow the production of substantially freely specifiable profile modifications of the workpiece.
In an alternative, extended embodiment of the present disclosure, the topological modification of the surface geometry of the tool in the generating pattern can be described at least approximately in a first direction of the tool as a constant, linear or quadratic function whose coefficients in the width direction of the tool are given by coefficient functions FFtC,1 for the constant portion, FFtL,1 for the linear portion, and/or FFtQ,1 for the square portion. Such modifications can likewise still be manufactured simply and can extend the usable region of the tool. In the event that the coefficient functions FFtL,1 for the linear portion and FFtQ,1 for the quadratic portion are equal to 0, the second alternative corresponds to the first alternative. However, at least one coefficient function and further optionally both coefficient functions FFtL,1 for the linear portion and FFtQ,1 for the quadratic portion is/are optionally different from (and thus not equal to) 0.
The first direction of the modification of the tool optionally corresponds to the direction of the line of action of the dresser during dressing both in the first alternative and in the second alternative. This allows a particularly simple production of the modification by a variation of the position between the dresser and the tool during the dressing process.
As already mentioned above, the method in accordance with the present disclosure permits the manufacture of profile modifications. A desired profile modification of the workpiece can therefore in particular be specified and can be produced by the generating machining on the tool within the framework of the present disclosure.
The desired profile modification and/or the properties of the desired profile modification are optionally freely specifiable within specific conditions. Alternatively or additionally, one of the following properties of the profile modification can be specified: crowning, profile angle deviation, tip relief and/or root relief. The following data can optionally be specified with respect to at least one of the above-named properties: size of the crowning, size of the profile angle deviation, amount and position of the tip relief, and amount and position of the root relief.
A plurality of the above-named properties and/or data can optionally be specified; further optionally, all of the above-named properties and/or data can be specified.
At least one input mask can further be provided having input boxes for at least one of the above-named properties and/or for their data. The input mask optionally has input boxes for a plurality of the above-named properties and/or their data, and further optionally has input boxes for all of said properties and/or their data.
Alternatively or additionally, the desired profile modification can also be freely specifiable as a continuous modification and/or at a plurality of rolling angles. If the modification is freely specifiable at a plurality of rolling angles, the extent of the modification is optionally interpolated between these rolling angles within the framework of the method in accordance with the present disclosure.
The topological modification of the tool in accordance with the present disclosure can optionally be produced in that the position of the dresser with respect to the tool is varied during dressing in dependence on the angle of rotation of the tool and/or on the tool width position. It is hereby possible to produce a topological modification during dressing, e.g. a modification whose value depends on the angle of rotation of the tool and/or on the tool width position. A topological modification is thereby produced such as was already shown in more detail above.
The generating method with which the workpiece is machined may be carried out in accordance with the present disclosure with a defined contact path on the tool, wherein the topological modification and/or the contact path is/are selected such that the topological modification on the tool has such a shape along the contact path that it produces a desired profile modification on the workpiece.
The topological modification can in particular be selected in dependence on the contact path, or the contact path can be selected in dependence on the topological modification, such that the topological modification on the tool has such a shape along the contact path that it produces a desired profile modification on the workpiece.
The machining with a defined contact path optionally comprises the machining with a defined initial shift position of the tool at the start of a machining stroke.
When machining a cylindrical workpiece, this initial shift position is optionally maintained over the entire machining stroke.
When machining a conical workpiece, the tool is shifted in contrast, optionally starting from the initial shift position, by such a diagonal ratio over the machining stroke such that the contact path is not shifted.
The present disclosure is based on the underlying recognition that the contact path which the contact point covers on the tool during the generating machining typically does not have the same direction as the line of action of the dresser on the dressing of the tool. A topological modification can therefore always be found for a defined contact path in accordance with the form defined in more detail above which produces the desired modification along this contact path. In the simplest case, in which the modification along the line of action with the dresser is constant on the tool, the desired modification along the contact path defines the form of the function FFt1 or, for the extended case, optionally defines the coefficient function FFtC,1 for the constant portion of the modification. Substantially any desired profile modifications can hereby be produced in accordance with the present disclosure.
The method in accordance with the present disclosure can in particular comprise the following steps:                specifying a desired profile modification on the workpiece;        determining the modification of the tool along a defined contact path required for producing the desired profile modification on the workpiece;        determining a topological modification of the tool which corresponds to the modification determined in this manner along the contact path; and/or determining the variation of the position of the dresser with respect to the tool during the dressing of the tool suitable for providing a topological modification which corresponds to the modification determined in this manner along the contact path.        
The topological modification is optionally produced in that the position of the dresser with respect to the tool during dressing is varied in dependence on the angle of rotation of the tool and/or on the tool width position. The variation is further optionally determined or takes place such that the specific modification results at the point of intersection between the line of action of the dresser with the tool and the contact path of the tool with the workpiece respectively given with a specific angle of rotation of the tool and at a specific tool width position, said specific modification then producing the desired modification on the workpiece within the framework of the generating machining method.
The defined contact path is optionally specified by a defined initial shift position of the tool.
Provision is further optionally made that a determining of the points of contact between the workpiece and the tool forming the contact path in the generating machining first takes place for determining the modification of the tool along a contact path suitable for producing the desired modification on the workpiece. The points of contact or the contact path hereby formed is optionally determined analytically.
The position of the line of action of the dresser into the tool can furthermore be determined in dependence on the angle of rotation of the tool and/or on the tool width position for determining the variation of the position of the dresser with respect to the tool suitable for providing a topological modification. The determination can take place, for example, by a dressing simulation.
The direction of the line of action is optionally assumed as constant and in particular as independent of the modification used. This in particular applies to involute gearings in a good approximation.
Alternatively, the influence of a modification on the direction of the line of action can be taken into account. Such a taking into account can in particular take place for non-involute gearings in which the influence of a modification on the direction of the line of action can be greater. It must furthermore be taken into account with non-involute gearings that the line of action typically no longer corresponds to a straight line.
A profile modification produced in accordance with the present disclosure can also have other modifications superposed on it.
In accordance with a first aspect, the machining kinematics can be modified within the framework of the generating method to superpose a modification produced by the modification of the machining kinematics on the modification on the workpiece produced by the topological modification of the tool. The profile modification produced in accordance with the present disclosure can in particular have a naturally twisted tooth trace modification superposed on it.
A modified dresser can furthermore be used for dressing the tool within the framework of the present disclosure. The modification of the tool produced by the modification of the dresser can have a topological modification superposed on it which is produced in that the position of the dresser with respect to the tool is varied during dressing in dependence on the angle of rotation of the tool and/or on the tool width position. The topological modification can in particular be determined and produced in the same manner as has already been described above.
The topological variation is optionally selected such that the superposition of the modifications on the tool along a selected contact path with the workpiece corresponds to a modification along the contact path suitable or producing a desired profile modification on the workpiece. In this embodiment of the present method, the fact that a modified dresser is used for dressing therefore has no influence on the form of the modification along the selected contact path. The topological modification is rather also selected here such that it has a form along this selected contact path which produces the desired profile modification within the framework of the generating machining.
The use of a modified dresser within the framework of the present disclosure can, however, be of advantage if only a modified dresser is available for a specific dressing job. It can then be used in accordance with the present disclosure since the modification of the dresser is compensated with respect to the modification along the contact path and thus the profile modification.
The selection of a modified dresser can also have relevance within the framework of the present disclosure in that, in addition to the selected contact path with respect to which the topological profile modification was produced, even further contact paths are used for a generating machining at which the modification is thus no longer optimal. The quantity or the region of contact paths which still produces modifications on the workpiece within the permitted tolerance, can optionally be extended by the use of a modified dresser.
A dresser can furthermore be used in accordance with the present disclosure for dressing the tool which was designed for a tool having a different macrogeometry, and which was in particular designed for a tool having a different diameter and/or a different number of threads.
Such dressers which were designed for a different tool produce a deviation from the desired modification on the workpiece without a modification of the dressing process. The modification of the surface geometry of the tool produced by the non-matching dresser is therefore optionally compensated in accordance with the present disclosure at a selected contact path with the workpiece in that the position of the dresser with respect to the tool during dressing is suitably varied in dependence on the angle of rotation of the tool and/or on the tool width position. The unwanted modification produced by the non-matching dresser can thus be compensated for at least a contact path. The generating machining method is then optionally carried out with the selected contact path for which the modification was compensated.
Such a method can in particular be used when the diameter of the tool has reduced after a plurality of dressing procedures such that the dresser no longer matches the tool or such that the modifications produced by the reduced diameter of the tool during dressing are outside the permitted tolerance. In accordance with the prior art, such tools having reduced diameters either have to be dressed by a different dresser or cannot continue to be used. The present disclosure allows the further use of such tools since the non-permitted modifications can at least be compensated for a contact path.
The present disclosure comprises, in a second, independent aspect, a method of producing a workpiece having a desired gearing geometry by means of a suitably dressed tool comprising the steps:                specifying a desired profile modification of the workpiece;        selecting a combination from a plurality of combinations of a dresser and a tool which produces the smallest deviations from the desired profile modification without any modification of the dressing process;        a modified dressing of the tool with the dresser in line contact for producing a topological modification of the tool to compensate the deviations; and        generating machining the workpiece with the dressed tool with a contact path unchanged over the machining stroke to produce the desired profile modification.        
As already presented above, it can be of advantage to select a combination of dresser and tool which already produces a profile extent on the workpiece without the use of the method in accordance with the present disclosure, said profile extent having the lowest possible deviations from the desired profile modification. Only smaller deviations or a smaller modification hereby have to be produced by the use of the method in accordance with the present disclosure and by the topological modification of the tool used. This can in particular have the advantage that the quantity or the region of contact paths which can still be used within a permitted tolerance becomes larger.
The dressers and/or tools are optionally an at least partly specified or already existing range. A selection is optionally made from this range to find a combination of dresser and tool which is the best possible match.
The method in accordance with the present disclosure in accordance with the second aspect is optionally carried out such has already been described in more detail above with respect to the first aspect. The determination and/or production of the topological modification of the tool and the generating machining is/are in particular carried out such as has already been shown in more detail above.
In a third aspect, likewise independent, of the present disclosure, it comprises a method of manufacturing one or more workpieces having a desired gearing geometry by means of a suitably dressed tool, wherein, after the carrying out of one or more machining steps, the tool is respectively dressed before further machining steps are carried out at the same workpiece or at further workpieces. Provision is made in accordance with the present disclosure that in a later dressing process, a different topological modification of the tool is produced with respect to an earlier dressing process. The diameter of the tool which reduces in size due to the plurality of dressing processes can thus in particular be taken into account within the framework of the present disclosure in the production of the topological modification. The topological modification can in this respect in particular be produced for the respective dressing process such that a modification is adopted along a specified contact path which produces a desired profile modification within the framework of the generating grinding of the workpiece.
The method in accordance with the third aspect can optionally be combined with a method in accordance with the first and/or second aspect. In this respect, the topological dressing and/or the generating machining can in particular be carried out such as has already been explained in more detail above.
Advantageous embodiments of the present disclosure which can be used in any of the of the above-described aspects of the present disclosure as well as in any desired combinations of these aspects will be shown in more detail in the following:
As already presented in more detail above, the present method allows a specified profile modification to be produced substantially exactly in a generating machining with a specified initial shift position or a contact path defined by this initial shift position. In contrast, with initial shift positions or with a contact path which are/is shifted with respect to such an ideal initial shift position or such an ideal contact path, deviations from the desired profile modification result since the topological modification can only have exactly the desired form for one contact path or for one initial shift position. In many cases, however, there are shifted contact paths or initial shift positions with which the desired profile modification can still be produced within the permitted tolerance. The tool or the tool width can hereby be utilized better.
In accordance with the present disclosure, during a machining of one or more workpieces, at least one stroke can be carried out with a first initial shift position of the tool and/or with a first contact path and at least one second stroke can be carried out with a second initial shifted shift position of the tool and/or with a second, shifted contact path. The tool width can hereby be utilized better.
The first initial shift position and/or the first contact path is optionally less shifted with respect to an ideal initial shift position or an ideal contact path than the second initial shift position and/or the second contact path. The first initial shift position can in particular correspond to the ideal initial shift position and/or the first contact path can correspond to the ideal contact path. In accordance with the present disclosure, a generating machining can therefore be carried out, on the one hand, with the ideal initial shift position or with the ideal contact path. To utilize the tool more uniformly, work can, however, also be carried out using a second initial shift position or a second contact path shifted with respect to such an ideal initial shift position or such an ideal contact path, in particular when this second initial shift position and/or this second contact path produces a modification which is within a permitted tolerance with respect to the desired profile modification.
In a possible embodiment of the present disclosure, a rough machining step, in particular a roughing step, can be carried out using the second initial shift position. In such a rough machining step, the permitted tolerances are larger with respect to the profile shape so that the deviation from the ideal initial shift position or the ideal contact path and the deviations from the desired modifications hereby produced can be tolerated more easily. A fine machining step is furthermore optionally carried out using the first initial shift position and/or the first contact line. The permitted tolerances are smaller in the fine machining step so that work should be carried out closer to the ideal contact line or to the ideal initial shift position here or with the ideal initial shift position and/or the ideal contact path.
As already shown above, by the selection of a dresser which produces a modification on the tool without using the present method, with said modification producing a modification on the workpiece in the generating method which comes as close as possible to the desired modification, the usable range of initial shift positions and/or contact lines can be increased. The present disclosure, however, also provides possibilities independently of this to increase the usable range by a corresponding design of the topological modification.
In accordance with the present disclosure, the modification of the tool can be at least approximately describable in the generating pattern by a linear and/or quadratic function at least locally in a first direction of the tool, wherein the coefficients of this linear and/or quadratic function are formed in a second direction of the tool which extends perpendicular to the first direction by coefficient functions FFtC,1 for the constant portion and FFtL,1 for the linear portion and/or FFtQ,1 for the quadratic portion. Such a modification with a linear and/or quadratic portion has further degrees of freedom with respect to a modification which is constant in the first direction, said further degrees of freedom optionally being able to be used for extending the usable range.
In accordance with the present disclosure, the coefficient function FFtC,1 for the constant portion is determined such that a desired profile modification is produced in the generating grinding at a specified initial shift position and/or with a specified contact path. The coefficient functions FFtL,1 for the linear portion and/or the coefficient function FFtQ,1 for the quadratic portion is/are then optionally determined such that the deviations from the desired profile modification are minimal which arise on the workpiece in a generating machining with at least one shifted initial shift positions and/or contact path and/or with at least one band or one range of initial shift positions or contact paths. The determination of the coefficient functions can take place by a compensation calculation, for example.
In a possible embodiment of the present disclosure, the deviations can be weighted differently in dependence on the generating path to take account of different tolerances along the profile.
The spacing of the shifted shift positions and/or contact paths or the width of the band can furthermore be determined iteratively such that the deviation arising on the workpiece still lies within a specified tolerance in all contact paths.
The present disclosure provides even further possibilities to be able to utilize the tool width as much as possible.
In accordance with the present disclosure, the tool can have at least one region having a first topological modification and a second region having a second topological modification, wherein the first topological modification along a contact path with the workpiece in a first initial shift position is identical to the second topological modification along a contact path with the tool in a second initial shift position. The desired profile modification can hereby be produced exactly in this case at the first and second initial shift positions.
In this respect, at least one stroke can be carried out with the first initial shift position of the tool during a machining of one or more workpieces and at least one second stroke with the second initial shift position of the tool. Both the first region and the second region of the tool are hereby used within the framework of the present disclosure to machine a workpiece.
The first region optionally comprises the complete contact path with the workpiece in the first initial shift position and the second region likewise comprises a complete contact path with the workpiece in the second initial shift position. The two regions can thus each be used to produce a complete profile of the workpiece and to provide the desired profile modification.
In a preferred embodiment of the present disclosure, the first topological modification is identical with the second topological modification. A plurality of identical topological modifications are in particular thus arranged next to one another on the tool. The tool width can hereby be used better.
In accordance with the present disclosure, a desired profile modification of the tool can be specified and a modification of the tool suitable for the production of this desired modification and/or a suitable variation of the position of the dresser with respect to the tool can be determined during dressing in dependence on the angle of rotation of the tool and/or on the tool width position. The modification of the tool along a contact line between the tool and the workpiece is optionally determined from the desired profile modification of the workpiece by means of an inverse of an association function which describes the mapping of the surface of the tool to the surface of the workpiece on the generating grinding with a specific initial shift position of the tool. The determination optionally takes place using a function which analytically describes the mapping of the surface of the tool to the surface of the workpiece on the generating grinding. This function in particular optionally associates a point along the contact path on the workpiece and thus a point along the profile on the workpiece with each point along the contact path on the tool.
In accordance with the present disclosure, the tool is optionally dressed in a modified form by means of a profile roller dresser and/or a form roller dresser. Such a profile roller dresser and/or form roller dresser optionally has an axis of rotation and a profile rotationally symmetrical about this axis of rotation.
The dressing optionally takes place in accordance with the present disclosure in line contact with the tool. The topological modification in accordance with the present disclosure is designed such that a contour dressing is not necessary for its production. The modification can rather also be produced during a dressing in line contact in that, as described above, the position between the dresser and the tool is varied in dependence on the tool width position and/or on the angle of rotation of the tool.
In accordance with a first variant of the present disclosure, the profile roller dresser or form roller dresser can be in contact with the tooth of the tool during the dressing from the root region to the tip region so that the modification is produced over the total tooth depth in one stroke. In a second, alternative variant, the profile roller dresser or form roller dresser can be in contact with the tooth of the tool only in part regions between the root and the tip during dressing so that the specific modification takes place over the total tooth depth in a plurality of strokes and at a respective different relative positioning of the dresser. Such a dressing of the tool in a plurality of strokes has the advantage in principle that an even greater class of topological modifications can be produced. However, this is not necessary for the carrying out of the present disclosure since a topological modification suitable for the method in accordance with the present disclosure can also be produced in a single stroke. The dressing in a plurality of strokes can, however, also have technological advantages, for example when no dresser is available which would have a sufficient profile length.
The production of the topological modification of the tool in accordance with the present disclosure can take place in that one or more of the following corrections of the axial movements with respect to the conventional dressing kinematics are carried out:                a) varying the center distance of the dresser from the tool in dependence on the angle of rotation of the tool or on the tool width position, e.g. varying the feed in dependence on the angle of rotation of the tool and/or on the tool width position;        b) varying the axial feed of the tool or of the dresser in dependence on the angle of rotation of the tool and/or on the tool width position, e.g. varying the shift movement of the dresser or of the tool in dependence on the angle of rotation of the tool and/or on the tool width position;        c) varying the axial cross angle of the tool and of the dresser in dependence on the angle of rotation of the tool and/or on the tool width position, e.g. a variable pivot movement of the dresser relative to the tool in dependence on the angle of rotation of the tool and/or on the tool width position; and        d) varying the tool speed in dependence on the angle of rotation of the tool and/or on the tool width position. The angle of rotation of the tool is typically fixedly coupled to the tool width position to shift the profile produced on the tool by the dresser along the tooth flank. Modifications can therefore be produced by varying the ratio between the angle of rotation of the tool and the tool width position.        
Alternatively or additionally, the modified dressing of the tool can take place in that the dresser is fed more or less in dependence on the angular position of the tool and/or on the tool width position or in that the tool is fed more or less onto the dresser, or vice versa, in dependence on its angular position and/or on the tool width position.
Furthermore, at least three degrees of freedom, and optionally four or five degrees of freedom, can be used during the relative positioning between the dresser and the tool for producing the desired modification. The degrees of freedom are optionally set independently of one another for producing the desired modification. Optionally, at least three, four or all of the following five degrees of freedom can be used: angle of rotation of the tool; axial position of the tool; y position of the dresser; center distance; and/or axial cross angle. The axial position of the tool, e.g. the tool width position, is optionally used to displace the contact line of the dresser. Two, three of four degrees of freedom of the remaining four degrees of freedom can now be set independently of one another to produce the specific modification along the contact line.
The present disclosure furthermore comprises a tool for carrying out a method in accordance with the present disclosure as was shown above. The tool in accordance with the present disclosure has at least one first region with a first topological modification. The topological modification is configured in accordance with the present disclosure such that it produces the desired modification on the workpiece along a contact path with the workpiece during generating machining with a contact path unchanged over the machining stroke. The topological modification optionally has an embodiment such as was described in more detail above.
A tool in accordance with the present disclosure can have only one region with a single topological modification in a possible embodiment. To utilize the tool width better, the tool in accordance with the present disclosure can, however, furthermore have a second region with a second topological modification, wherein the first topological modification along a contact path with the workpiece having a first initial shift position is identical with the second topological modification along a contact path with the workpiece in a second initial shift position. The tool can thus be used with the first and second initial shift positions in each case for producing an identical profile. The tool can furthermore also have an unmodified region beside the modified region. The unmodified region may be used for a rough machining of the workpieces, whereas the modified region may be used for a fine machining of the workpieces. This provides the advantage that in this embodiment, the number of machined workpieces between the dressing cycles is larger since the main machining performance is produced by the unmodified roughing region and only the last quality-determining cuts take place in the modified finishing region and this thus does not wear so fast.
The first region in each case comprises in accordance with the present disclosure the respective complete contact path with the workpiece at the first initial shift position and/or the second region comprises the respective complete contact path with the workpiece at the second initial shift position.
In accordance with the present disclosure, the first topological modification can optionally be identical to the second topological modification. In this case, the tool has at least two identical topological modifications next to one another.
The present disclosure furthermore comprises a gear manufacturing machine for carrying out a method such as was described in more detail above. The gear manufacturing machine in this respect optionally has a control (e.g., a control system including a control unit, sensors and/or input devices, and actuators, the control unit including a processor and non-transitory memory having instructions stored therein for controlling the actuators to in turn control operation of the gear manufacturing machine and the components thereof) for carrying out a method in accordance with the present disclosure.
The gear manufacturing machine in accordance with the present disclosure can in particular comprise an input function via which a desired modification of a workpiece is specifiable, wherein the gear manufacturing machine optionally has a determination function which determines a modification of the tool suitable for the production of this desired modification and/or a suitable variation of the position of the dresser with respect to the tool during the dressing in dependence on the angle of rotation of the tool and/or on the tool width position. The gear manufacturing machine can furthermore have a dressing function which produces a modification of the tool suitable for the production of the desired modification of the workpiece during the dressing on the tool.
The gear manufacturing machine can in particular have a workpiece holder and a tool holder which are each rotatable about an axis of rotation and which are movable relative to one another over further axes of movement of the gear manufacturing machine to carry out a generating machining in accordance with the present disclosure. The gear manufacturing machine further optionally has a dresser holder which is likewise movable about an axis of rotation to dress a tool with the dresser. The tool can be located in the tool holder, the workpiece holder or in a separate further holder while it is being dressed. The gear manufacturing machine optionally has axes of movement to vary the relative position between the dresser and the tool in accordance with the present disclosure during dressing.
The present disclosure further comprises a computer program having an input function for inputting data with respect to a desired modification of the workpiece and having a function for determining a topological modification of the tool suitable for producing this desired modification and/or a suitable variation of the position of the dresser with respect to the tool during dressing in dependence on the angle of rotation of the tool and/or on the tool width position such that the desired modification of the workpiece can be produced by generating machining using the topologically modified tool with a contact path unchanged over the machining stroke. For the case of conical workpieces, the computer program can furthermore have a function to determine the diagonal ratio in a single-flank generating machining for the left and/or right flank such that the contact path is not shifted on the tool during the machining, and optionally has a function to determine the geometry of the tool, in particular the conical angle and/or the profile angle, such that the same diagonal ratio results for the left and right flanks and optionally also determines this diagonal ratio. The computer program in accordance with the present disclosure can, for example, be stored on a data carrier or in a memory. The computer program can optionally be installable on a gear manufacturing machine and/or can have an output function for data for use on a gear manufacturing machine. The functions of the computer program optionally implement a method such as was presented in more detail above.
The input function of a gear manufacturing machine in accordance with the present disclosure or a computer program in accordance with the present disclosure optionally allows the specification of a desired profile modification, wherein the desired profile modification and/or its properties is/are optionally specifiable within specific conditions. Alternatively or additionally, at least one of the following properties of the profile modification can be specified: crowning, profile angle deviation, tip relief and/or root relief.
The following data can optionally be specified with respect to at least one of the following properties: size of the crowning, size of the profile angle deviation, amount and position of the tip relief, and amount and position of the root relief.
A plurality of the above-named properties and/or data can optionally be specified; further optionally, all of the above-named properties and/or data can be specified.
The gear manufacturing machine or the computer program optionally has an input mask having input boxes for at least one of the above-named properties and/or their data. The input mask optionally has input boxes for a plurality of the above-named properties and/or their data, and further optionally has input boxes for all of said properties and/or their data.
Alternatively or additionally, the desired profile modification can be freely specifiable as a continuous modification and/or at a plurality of rolling angles.
The input function, the determination function and/or the dressing function of the gear manufacturing machine in accordance with the present disclosure and/or of the computer program in accordance with the present disclosure are optionally configured such that they implement a method in accordance with the present disclosure such as is described above. Optionally, the gear manufacturing machine and/or the computer program in particular carries/carry out the determinations such as was described in more detail above with respect to the method in accordance with the present disclosure.
The present disclosure can in principle be used with any desired generating methods for machining a workpiece. It is, however, optionally used in a generating grinding method, in particular for the hard fine machining of a workpiece.
The workpieces can be any desired toothed workpieces. The present disclosure is optionally used for manufacturing gear wheels. The gear wheels optionally have a spur gear gearing. The gear wheels can have an internal gearing or an external gearing. The gearing can be a straight gearing or a helical gearing. The workpieces or the gear wheels can have a cylindrical or a conical base shape.
A grinding worm is optionally used as the tool. The grinding worm is optionally dressable and, for example, has a grinding body composed of a corundum material.
The present disclosure can be used both for manufacturing symmetrical gearings and for manufacturing asymmetrical gearings.
The present disclosure can furthermore be used for manufacturing cylindrical gearings and for manufacturing conical gearings.
Both a cylindrical grinding worm and a grinding worm having a conical base body can be used as the tool.
The present disclosure is optionally used for producing an involute gearing. The present disclosure can, however, also be used for producing non-involute gearings.
The dressing in accordance with the present disclosure optionally takes place on two flanks. The machining of the workpiece furthermore optionally also takes place on two flanks. Work is optionally carried out on one flank in the manufacture of a conical gearing with a cylindrical tool.